Process - a vertical line of cells below the apical surface and a cell or two -at- the apical surface die ( apoptosis ) forming a shaft. Cells at the bottom of the shaft die and form a lumen. Blood vessels then make their way to the lumen so material from the glands can be carried to the bloodstream and lymph system.

Rer produce proteins then sends them to the golgi apparatus which packages them and sends them to the glands which are brought to the gland, changed, then discharged into the blood and lymph systems and carried to different parts of the body.

What are the two major classes of glands?

Endochrine - these are ductless glands, they secrete hormones directly into the tissue fluids around them.

Exochrine - Exochrine glands do have ducts and secrete their products onto body surfaces or into body cavities. The secretions of exochrine glands act at the sites they are excreted to. Mucus, sweat, oil, salivary, bile, etc.

The glands produce hormones, secrete to tissue fluid, hormones make way to capillaries in tissues, carried to bloodstream, to capillaries in other part of body, dispersed into tissue fluids near target site, then find their way to target cell.

Endochrine glands can be difficult to identify since they don't all have the same structure. What are a few examples of what different endochrine glands look like?

Adrenal cortex - An adrenal gland sits on top of each kidney, they are made up of an outer cortex surrounding an inner medula. Glands in the adrenal cortex often form rows / lines / sheets, or "cords" of glands.

Thyroid gland - Multicellular, the cells form spheres / globs with the free surface facing inward and the basal surface outward, connected to the connective tissue. Inside the sphere the hormone is stored, attached to a protein for storage purposes. When ready to be released the protein is broken off and the hormone is send on its way through the body. They look like large globs with a border of nuclei around the border at cross section.

What are cytokines?

Cytokines are substances secreted by glands ( but not endochrine glands ) that act as signaling molecules to facilitate communication between cells. The immune system uses these secretions to target cells in need of immune system aid so that other substances of the immune system can locate and aid the target cells. ( terrible description, having trouble finding info on this )

What are Paracrine cells?

Paracrine cells release hormones that target other, different cells in their immediate vicinity. The gland releases the hormone into the surrounding tissue fluid and nearby cells then take it up.

What are autocrine cells?

Autochrine cells are glands that secrete hormone that is released into the surrounding tissue fluid and then taken back up by the cell that produced it.

What are unicellular glands?

Unicellular glands are glands that are made up of only one cell. They are always found in the epithelia, they are usually goblet cells that secrete mucus, found in airways and GI tract.

What are myoepithelial cells?

Myoepithelial cells are muscle cells that surround the base ( lumen ) of multicellular glands and squeeze it to force out stuff

Gland classification
-Simple Alveolar ( acinar )

Simple Alveolar glands have a duct decending to a bulb shaped cavity ( alveoli ) at the base. Different from simple tubular in that it is not just a tube.

Gland classification
-Simple branched alveolar / acinar

Simple branched alveolar glands have a single duct with several alveoli emptying into it. Sebacious glands are one example.

Gland classification
-Simple tubular

Simple tubular glands are pretty much just little tubes with the base being about the same dimmension and shape as the duct. Found in colon.

Gland classification
-Simple branched tubular

Simple branched tubular glands have several tubular shaped secretory units that empty into a single duct. Found in stomach.

Gland classification
-Simple / compound tubuloalveolar

Simple and compound tubuloalveolar glands are glands that are somewhere between alveolar and tubular glands but look like expanded tubes rather than skinny tubes or round alveolar.

Gland classification
-Simple coiled tubular

Simple coiled tubular glands are much like simple tubular glands except that they are kind of corkscrew shaped. Sweat glands are an example of simple coiled tubular glands.

Gland classification
-Compound alveolar

Compound alveolar glands are made of several groups of branched alveolar, each with its own duct emptying into a main duct.

Gland classification
-Compound tubular

Compound tubular glands are made of groups of branched tubular glands, each with its own duct emytying into a single main duct.

Compound glands
-Parenchyma

Parenchyma is the gland secretory unit and duct. It is the functional parts of the gland, the parts that actively do something.

Compound glands
-Stroma

Stroma is the supporting connective tissues of the gland.

Compound glands
-Duct terminology

From small and outside working in and larger for compound alveolar glands:

Serous demilunes are cresent shaped cluster of serous cells around a mucous secretory unit. They make the watery portion of mucous?

Modes of secretion
-Merocrine

Merocrine is a process of glandular secretion where the epithelial cells making up the gland produce the product and express it into the lumen or duct via exoycytosis without loseing any cytoplasm in the process.

Modes of secretion
-Apocrine

Apocrine is a method of secretion wherein the secretory cell of the gland manufactures the secretion, pushes it to the apical surface of the cell, cell membrane wraps around the secretion, pinches off and forms a vescicle of unit membrane and secretion.

Modes of secretion
-Holocrine

Holocrine is a method of gland secretion where the secretory cells produce their secretions and expell it into the lumen / gland by simply rupturing and spilling its contents ( the secretion manufactured, cytoplasm, bits of the cell itself ) into the gland.

What is regulated pathway in regards to glands?

Regulated pathway is where the gland cell stores its secretion until it recieves a signal to release it.

What is constitutive pathway?

Constitutive pathway is where the gland cell continuously releases its secretion.